Development of liposome immunoassay for salmonella spp. using immunomagnetic separation and immunoliposome.
The ability to detect Salmonella spp. is essential in the prevention of foodborne illness. This study examined a Salmonella spp. detection method involving the application of immunomagnetic separation and immunoliposomes (IMS/IL) encapsulating sulforhodamine B (SRB), a fluorescent dye. A quantitative assay was conducted by measuring the fluorescence intensity of SRB that was produced from an immunomagnetic bead-Salmonella spp.-immunoliposome complex. The results indicated detection limits of 2.7x10(5) and 5.2x10(3) CFU/ml for Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) and Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium), respectivley. The signal/noise ratio was improved by using 4% skim milk as a wash solution rather than 2% BSA. In addition, higher fluorescence intensity was obtained by increasing the liposome size. Compared with the conventional plating method, which takes 3-4 days for the isolation and identification of Salmonella spp., the total assay time of 10 h only including 6 h of culture enrichment was necessary for the Salmonella detection by IMS/IL. These results indicate that the IMS/ IL has great potential as an alternative rapid method for Salmonella detection.
Shin
Junghee
J
School of Food Science/Technology and Food Service Industry, College of Natural Resources, Yeungnam University, Gyeongbuk 712-749, Korea.
Kim
Myunghee
M
D006801:Humans; D007118:Immunoassay / Q000379:methods*; D018189:Immunomagnetic Separation / Q000379:methods*; D008081:Liposomes / Q000737:chemistry / Q000276:immunology; D012480:Salmonella Infections / Q000382:microbiology*; D019779:Salmonella enterica / Q000302:isolation & purification*; D012680:Sensitivity and Specificity
D008081:Liposomes